1. Field of the Disclosure
The present disclosure relates to a relay, and particularly, to a relay that prevents a moving contact from deviating from a fixed contact due to inter-electron repulsion.
2. Background of the Disclosure
As well known, an electronic switching device is a type of electrical contact switching device that supplies or cuts off a current, and may be applied to various industrial equipment, machines, and vehicles.
FIG. 1 is a cross-sectional view illustrating a related art relay.
As illustrated in FIG. 1, the related art relay includes a contact part 20, which switches on or off an internal circuit of an external box, and a driver 10 that drives the contact part 20.
The contact part 20 includes a power fixed contact 22, a load fixed contact 24, and a moving contact 26 which is attached to or detached from the power fixed contact 22 and the load fixed contact 24 (hereinafter referred to as fixed contacts).
The driver 10 is configured with, for example, an actuator that generates a driving force with an electric force.
In more detail, the driver 10 is configured with a solenoid that includes a coil 12 that generates a magnetic force with power applied thereto to form a magnetic field space, a fixed core 14 that is fixedly disposed in the magnetic field space formed by the coil 12, a movable core 16 that is movably disposed in the magnetic field space so as to approach or be separated from the fixed core 14, and a shaft 18 that mechanically connects the movable core 16 to the moving contact 26.
One end of the shaft 18 is coupled to the movable core 16, and the other end is connected to the moving contact 26 through the fixed core 14.
In this case, a through hole 14a may be formed at a center of the fixed core 14 in order for the shaft 18 to pass through the through hole 14a. 
A return spring 15, which applies an elastic force in a direction where the movable core 16 deviates from the fixed core 14, is provided between the fixed core 14 and the movable core 16.
Hereinafter, operational effects of the related art relay will be described.
When power is applied to the coil 12, the coil 12 generates a magnetic force.
The movable core 16 is moved by the magnetic force in a direction (i.e., a direction (an up direction in the drawing) approaching the fixed core 14) where a magnetic resistance is reduced.
In this case, the return spring 15 is charged between the fixed core 14 and the movable core 16.
The shaft 18 is moved, by a movement of the movable core 16, in a direction (an up direction in the drawing) where the other end of the shaft 18 deviates from the fixed core 14.
The moving contact 26 is moved, by a movement of the shaft 18, in a direction (an up direction in the drawing) contacting the fixed contacts 22 and 24, and thus contacts the fixed contacts 22 and 24.
When the moving contact 26 contacts the fixed contacts 22 and 24, a circuit is connected in order for a current to flow, the current applied to a power source is supplied to a load through the power fixed contact 22, the moving contact 26, and the load fixed contact 24.
When the supply of power to the coil 12 is stopped, generation of a magnetic force by the coil 12 is stopped.
When generation of the magnetic force by the coil 12 is stopped, the movable core 16 is moved, by an elastic force of the return spring 15, in a direction (a down direction in the drawing) deviating from the fixed core 14.
In this case, the return spring 15 is discharged between the fixed core 14 and the movable core 16.
The shaft 18 is moved, by a movement of the movable core 16, in a direction (a down direction in the drawing) where the other end of the shaft 18 approaches the fixed core 14.
The moving contact 26 is moved, by a movement of the shaft 18, in a direction (a down direction in the drawing) deviating from the fixed contacts 22 and 24, and thus is detached from the fixed contacts 22 and 24.
When the moving contact 26 is detached from the fixed contacts 22 and 24, a circuit is broken, and thus, the supply of power is stopped.
However, in the related art relay, when a short circuit current occurs, the moving contact 26 deviates from the fixed contacts 22 and 24 due to inter-electron repulsion.
Therefore, a pickup voltage increases, and the driver 10 is driven with the increased pickup voltage so that the moving contact 26 does not deviate from the fixed contacts 22 and 24 due to the inter-electron repulsion. However, considerable electric energy is consumed when driving the driver 10 with the increased pickup voltage.